1. Field of the Invention
This invention relates to weaving and more particularly to an improved bifurcated center brace for a loom harness.
2. Description of the Prior Art
It is well known that weaving consists of interlacing two sets of threads together at right angles to form a continuous web. For example, to form a plain weave, the warp yarns or the lengthwise yarns and the filling yarns or the crosswise yarns intersect so that ultimately the warp yarn goes over one and then under one filling yarn. The filling yarn does likewise with respect to the warp. The minimum number of harnesses required to produce this weave is two. Alternate warp yarns are threaded into harness one and the remaining alternate yarns are threaded into harness two.
Each individual yarn is threaded through a "heddle" or needle. The heddles are held in a frame called the harness. Each harness can be raised or lowered as desired, thus controlling the position of its heddles and warp yarns. Thus the harnesses will shift so that other sets of warp yarns are respectively raised and lowered and a shuttle motion causes the filling yarn to pass under the warp yarns which are raised by the harnesses and to pass over those warp yarns that are retained in their original lower positions by their remaining harnesses. Then the harnesses will shift so that other sets of warp yarns are respectively raised and lowered and the shuttle action again inserts filling yarn. In this way the fabric is woven.
A problem associated with the frames or harnesses has been the installation and removal of one or more center brace members which extend between the upper and lower members of the harness or frame members. The center brace member must provide proper support for the frames as they move up and down during the operation, while at the same time it is essential that the center brace member or members, depending upon the length of the harness, be able to be installed or detached rapidly and simply and without interfering with the yarns, heddles or other operating apparatus. It is particularly important that the center brace member provide sufficient support to the frame members without weakening the frame members.
Still another problem associated with the center brace member is that this member must be sufficiently strong but not too wide. It has been found that a wide brace member causes streaking of the cloth due to the close proximity of the center brace, in relation to the flat reeds or profile reed, depending on the loom construction. However, if the center brace members are relatively narrow there may be a problem from the standpoint of strength and support for the frame members. Furthermore, it is desirable that when installing or detaching the center brace members that there be a minimum of interference with the yarns and heddles described above.
A bifurcated center brace apparatus has been described in the prior art, but it is expensive and time consuming to manufacture because it can only be made of customized materials. Also, the design of the prior art device incorporates a relatively small opening that limits the movement of those harnesses having the widest shed opening, which ultimately prevents the shed from opening to its maximum distance.
Therefore, the major objective of this invention is to provide a center brace apparatus that overcomes the problems of the prior art discussed above and that is also easy and inexpensive to manufacture.